Portable navigation devices (PNDs) including GPS (Global Positioning System) signal reception and processing means are well known and are widely employed as in-car navigation systems. In essence, modern PNDs comprise:                a processor,        memory (at least one of volatile and non-volatile, and commonly both),        map data stored within said memory,        a software operating system and optionally one or more additional programs executing thereon, to control the functionality of the device and provide various features,        a GPS antenna by which satellite-broadcast signals including location data can be received and subsequently processed to determine a current location of the device,        optionally, electronic gyroscopes and accelerometers which produce signals capable of being processed to determine the current angular and linear acceleration, and in turn, and in conjunction with location information derived from the GPS signal, velocity and relative displacement of the device and thus the vehicle in which it is mounted,        input and output means, examples including a visual display (which may be touch sensitive to allow for user input), one or more physical buttons to control on/off operation or other features of the device, a speaker for audible output,        optionally one or more physical connectors by means of which power and optionally one or more data signals can be transmitted to and received from the device, and        optionally one or more wireless transmitters/receivers to allow communication over mobile telecommunications and other signal and data networks, for example Wi-Fi, Wi-Max GSM and the like.        
The utility of the PND is manifested primarily in its ability to determine a route between a start or current location and a destination, which can be input by a user of the computing device, by any of a wide variety of different methods, for example by postcode, street name and number, and previously stored well known, favourite or recently visited destinations. Typically, the PND is enabled by software for computing a “best” or “optimum” route between the start and destination address locations from the map data. A “best” or “optimum” route is determined on the basis of predetermined criteria and need not necessarily be the fastest or shortest route. The selection of the route along which to guide the driver can be very sophisticated, and the selected route may take into account existing, predicted and dynamically and/or wirelessly received traffic and road information, historical information about road speeds, and the driver's own preferences for the factors determining road choice. In addition, the device may continually monitor road and traffic conditions, and offer to or choose to change the route over which the remainder of the journey is to be made due to changed conditions. Real time traffic monitoring systems, based on various technologies (e.g. mobile phone calls, fixed cameras, GPS fleet tracking) are being used to identify traffic delays and to feed the information into notification systems.
The navigation device may typically be mounted on the dashboard of a vehicle, but may also be formed as part of an on-board computer of the vehicle or car radio. The navigation device may also be (part of) a hand-held system, such as a PDA (Personal Navigation Device) a media player, a mobile phone or the like, and in these cases, the normal functionality of the hand-held system is extended by means of the installation of software on the device to perform both route calculation and navigation along a calculated route. In any event, once a route has been calculated, the user interacts with the navigation device to select the desired calculated route, optionally from a list of proposed routes. Optionally, the user may intervene in, or guide the route selection process, for example by specifying that certain routes, roads, locations or criteria are to be avoided or are mandatory for a particular journey. The route calculation aspect of the PND forms one primary function provided, and the navigation along such a route is another primary function. During navigation along a calculated route, the PND provides visual and/or audible instructions to guide the user along a chosen route to the end of that route, that is the desired destination. It is usual for PNDs to display map information on-screen during the navigation, such information regularly being updated on-screen so that the map information displayed is representative of the current location of the device, and thus of the user or user's vehicle if the device is being used for in-car navigation. An icon displayed on-screen typically denotes the current device location, and is centered with the map information of current and surrounding roads and other map features being also displayed. Additionally, navigation information may be displayed, optionally in a status bar above, below or to one side of the displayed map information, examples of navigation information including the distance to the next deviation from the current road required to be taken by the user, the nature of that deviation possibly being represented by a further icon suggestive of the particular type of deviation, for example a left or right turn. The navigation function also determines the content, duration and timing of audible instructions by means of which the user can be guided along the route. As can be appreciated a simple instruction such as “turn left in 100 m” requires significant processing and analysis. As previously mentioned, user interaction with the device may be by a touch screen, or additionally or alternately by steering column mounted remote control, by voice activation or by any other suitable method.
A further important function provided by the device is automatic route re-calculation in the event that                a user deviates from the previously calculated route during navigation therealong,        real-time traffic conditions dictate that an alternative route would be more expedient and the device is suitably enabled to recognize such conditions automatically, or        if a user actively causes the device to perform route re-calculation for any reason.        
It is also known to allow a route to be calculated with user defined criteria; for example, the user may prefer a scenic route to be calculated by the device, or may wish to avoid any roads on which traffic congestion is likely, expected or currently prevailing. The device software would then calculate various routes and weigh more favourably those that include along their route the highest number of points of interest (known as POIs) tagged as being for example of scenic beauty, or, using stored information indicative of prevailing traffic conditions on particular roads, order the calculated routes in terms of a level of likely congestion or delay on account thereof. Other POI-based and traffic information-based route calculation and navigation criteria are also possible.
Although the route calculation and navigation functions are fundamental to the overall utility of PNDs, it is possible to use the device purely for information display, or “free-driving”, in which only map information relevant to the current device location is displayed, and in which no route has been calculated and no navigation is currently being performed by the device. Such a mode of operation is often applicable when the user already knows the route along which it is desired to travel and does not require navigation assistance.
More modern PNDs are being provided not only with the essential GPS antenna capable of receiving satellite signals, but also with a secondary mobile telecommunications antenna which effectively enables the device to become part of a mobile telecommunications network. Typically, the device may additionally be provided with an integrated or removable subscriber identity module (SIM) card on which are provided various data which are required to identify the device to the network and to encode and decode signals appropriate to that network to allow communication thereover.
It is also now known to provide PNDs and navigation systems with a further short-range wireless communication means, such as a Bluetooth® or Wi-Fi antenna which facilitates the pairing of the device with a similarly enabled other device, most commonly a mobile telecommunications handset.
Both of these technologies effectively permit a previously passive device, that is one which merely provides in-car navigation and route guidance functions based on the continuous and repeated determination of the current position of the device from the received GPS signals, to become an active device which is capable of transmitting information via a wider telecommunications network back to a centralized data processing service.
In this regard, U.S. Pat. No. 6,253,151 describes a feature whereby an end user of a navigation system that uses geographic data can easily report perceived errors or inaccuracies in the geographic data or other problems such as poor quality route calculation or guidance wirelessly. The end user uses a user interface of the navigation system to indicate the perceived error, inaccuracy, or other problem. The navigation system includes a report program that operates in response to the end user's indication. The report program collects information indicating the error, inaccuracy, or other problem and sends a report including the collected information to a geographic database developer. The geographic database developer can use the information in the report to update a geographic database.
The above system however is more concerned with ensuring that a centralized geographical or map database of a map data provider is as current and accurate as possible, as opposed to the provision of non-map related data, for example transient phenomena such as road works, temporary diversions and road closures, traffic congestion, accidents and other transient incidents or events which affect traffic flow and movement but do not ultimately represent a defect in the underlying map data.
The present applicant has realized that the facility for transmitting locally entered information specific to a location or range of locations offers a far greater spectrum of possibilities than mere map data correction and enhancement, especially when this information is made available by subsequent re-transmission to the wider installed user base of devices and systems.
Accordingly, it is an object of the present invention to provide a PND or navigation system, a method of operating such, and a computer program by means of which such are controlled, which provides an enhanced facility for reporting, among other things, transient phenomena and user-specific and/or local information, being that which is entered locally at the device or system.